Reply To: atlas: how2 'deform' (open) a sulcus? June 9, 2018 at 4:45 am #1289 sychoiParticipant Hi Dan, you can try cutting through the surfaces by pressing keys “x” “y” or “z” on the surface viewer. x : sagittal y : coronal z : axial The surface will cut through where ever your crosshairs are located on the volume slices.